fixes #2460 NPE on cursor from media lookup
fixes #2391 where signinHelper might not be init'd yet
added back in option to disable foreground service
some users really hate persistent notifications
small fixes for reported crashing on "exit"
improvements for foreground compat display (stop/start on conn status)
add support for different MediaStore media type columns
added comment about why signInHelper might be null
moved finish() back to proper place for launching lock screen
make sure ImUrl activity can handle a URI that we can't decode
Merge pull request #355 from n8fr8/v13_multiple_fixes

V13 multiple fixes